LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 4 of total 4

Search options

  1. Book ; Online: (Table 1) Grain size results, statistical parameters and magnetic susceptibility values of disturbed sediments from ODP holes 204-1249C and 204-1245B, supplementary data to: Pi?ero, Elena; Gr?cia, Eul?lia; Martinez-Ruiz, Francisca C; Larrasoa?a, Juan C; Vizcaino, Alexis; Ercilla, Gemma (2007): Gas hydrate disturbance fabrics of southern Hydrate Ridge sediments (ODP Leg 204): Relationship with texture and physical properties. Geo-Marine Letters, 27(2-4), 279-288

    Pi?ero, Elena / Ercilla, Gemma / Gr?cia, Eul?lia / Larrasoa?a, Juan C / Martinez-Ruiz, Francisca C / Vizcaino, Alexis

    2007  

    Abstract: Soupy and mousse-like fabrics are disturbance sedimentary features that result from the dissociation of gas hydrate, a process that releases water. During the core retrieval process, soupy and mousse-like fabrics are produced in the gas hydrate-bearing ... ...

    Abstract Soupy and mousse-like fabrics are disturbance sedimentary features that result from the dissociation of gas hydrate, a process that releases water. During the core retrieval process, soupy and mousse-like fabrics are produced in the gas hydrate-bearing sediments due to changes in pressure and temperature conditions. Therefore, the identification of soupy and mousse-like fabrics can be used as a proxy for the presence of gas hydrate in addition to other evidence, such as pore water freshening or anomalously cool temperature. We present here grain-size results, mineralogical composition and magnetic susceptibility data of soupy and mousse-like samples from the southern Hydrate Ridge (Cascadia accretionary complex) acquired during Leg 204 of the Ocean Drilling Program. In order to study the relationship between sedimentary texture and the presence of gas hydrates, we have compared these results with the main textural and compositional data available from the same area. Most of the disturbed analyzed samples from the summit and the western flank of southern Hydrate Ridge show a mean grain size coarser than the average mean grain size of the hemipelagic samples from the same area. The depositional features of the sediments are not recognised due to disturbance. However, their granulometric statistical parameters and distribution curves, and magnetic susceptibility logs indicate that they correspond to a turbidite facies. These results suggest that gas hydrates in the southern Hydrate Ridge could form preferentially in coarser grain-size layers that could act as conduits feeding gas from below the BSR. Two samples from the uppermost metres near the seafloor at the summit of the southern Hydrate Ridge show a finer mean grain-size value than the average of hemipelagic samples. They were located where the highest amount of gas hydrates was detected, suggesting that in this area the availability of methane gas was high enough to generate gas hydrates, even within low-permeability layers. The mineralogical composition of the soupy and mousse-like sediments does not show any specific characteristic with respect to the other samples from the southern Hydrate Ridge.
    Language English
    Dates of publication 2007-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Online
    Note This dataset is supplement to doi:10.1007/s00367-007-0077-z
    DOI 10.1594/PANGAEA.772949
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

    More links

    Kategorien

  2. Book ; Online: Rock magnetic susceptibility of ODP Leg 204 sites, supplementary data to: Larrasoa?a, Juan C; Roberts, Andrew P; Musgrave, Robert J; Gr?cia, Eul?lia; Pi?ero, Elena; Vega, Marta; Martinez-Ruiz, Francisca C (2007): Diagenetic formation of greigite and pyrrhotite in gas hydrate marine sedimentary systems. Earth and Planetary Science Letters, 261(3-4), 350-366

    Larrasoa?a, Juan C / Gr?cia, Eul?lia / Martinez-Ruiz, Francisca C / Musgrave, Robert J / Pi?ero, Elena / Roberts, Andrew P / Vega, Marta

    2007  

    Abstract: Mineral magnetic results and electron microscope observations from gas hydrate-bearing marine sediments cored at southern Hydrate Ridge during Ocean Drilling Program Leg 204 (Sites 1244 to 1252, Cascadia Margin, offshore Oregon) demonstrate that ... ...

    Abstract Mineral magnetic results and electron microscope observations from gas hydrate-bearing marine sediments cored at southern Hydrate Ridge during Ocean Drilling Program Leg 204 (Sites 1244 to 1252, Cascadia Margin, offshore Oregon) demonstrate that authigenic greigite and pyrrhotite formed as a byproduct of microbially-mediated diagenetic reactions in the sulphate, the anaerobic oxidation of methane (AOM), and the methanic/gas hydrate zones. Geochemical conditions favourable for formation and preservation of greigite and pyrrhotite appear to be a limited source of sulphide, whether it derives from microbially-driven sulphate reduction in the sulphate zone, in the AOM zone or in deep sediments undergoing AOM, so that pyritization reactions are not driven to completion. Our results indicate that rock magnetic identification of greigite and pyrrhotite should be useful for detecting ancient gas hydrate systems in the marine sedimentary record, because it can enable rapid screening of ancient sediments for potential horizons where methane and disseminated gas hydrates might have occurred. Formation of authigenic greigite and pyrrhotite at different depths within the gas hydrate stability zone also implies that the magnetization of the host sediments will have been acquired at variable times, which is likely to compromise paleomagnetic results from greigite- and pyrrhotite-bearing marine sediments.
    Language English
    Dates of publication 2007-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Online
    Note This dataset is supplement to doi:10.1016/j.epsl.2007.06.032
    DOI 10.1594/PANGAEA.707275
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

    More links

    Kategorien

  3. Book ; Conference proceedings ; Online: Magnetic susceptibility parameters of ODP Leg 204 sites, supplementary data to: Larrasoa?a, Juan C; Gr?cia, Eul?lia; Garc?s, Miguel; Musgrave, Robert J; Pi?ero, Elena; Martinez-Ruiz, Francisca C; Vega, Marta (2006): Rock magnetic identification of magnetic iron sulfides and its bearing on the occurrence of gas hydrates, ODP Leg 204 (Hydrate Ridge). In: Tr?hu, AM; Bohrmann, G; Torres, ME; Colwell, FS (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 204, 1-33

    Larrasoa?a, Juan C / Garc?s, Miguel / Gr?cia, Eul?lia / Martinez-Ruiz, Francisca C / Musgrave, Robert J / Pi?ero, Elena / Vega, Marta

    2006  

    Abstract: In this paper, we present a rock magnetic data set produced for sediments from Hydrate Ridge recovered during Ocean Drilling Program Leg 204. Our data set is based on several artificially induced magnetic properties that can be used as a diagnostic for ... ...

    Abstract In this paper, we present a rock magnetic data set produced for sediments from Hydrate Ridge recovered during Ocean Drilling Program Leg 204. Our data set is based on several artificially induced magnetic properties that can be used as a diagnostic for the presence of magnetic iron sulfides. The occurrence of magnetic iron sulfides within the gas hydrate stability zone in locations where gas hydrates are present seems to confirm previous interpretations linking formation of such minerals with generation of gas hydrate. Magnetic iron sulfides are also found at positions deeper than the gas hydrate stability zone. We suggest that these positions, which include intervals located just below the bottom-simulating reflector and also at deeper positions, may mark the former presence of gas hydrates that have been later dissociated as the gas hydrate stability zone moved upward through time. Detailed characterization of the magnetic iron sulfide mineralogy and comparison with sedimentological and geochemical data will be attempted for better determining the significance of magnetic iron sulfides in Hydrate Ridge sediments and their possible applications in the study of gas hydrates.
    Language English
    Dates of publication 2006-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Conference proceedings ; Online
    Note This dataset is supplement to doi:10.2973/odp.proc.sr.204.111.2006
    DOI 10.1594/PANGAEA.774816
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

    More links

    Kategorien

  4. Book ; Conference proceedings ; Online: Grain-size and bulk and clay mineralogy of ODP Leg 204 sediments, supplementary data to: Gr?cia, Eul?lia; Martinez-Ruiz, Francisca C; Pi?ero, Elena; Larrasoa?a, Juan C; Vizcaino, Alexis; Ercilla, Gemma (2006): Data report: Grain-size and bulk and clay mineralogy of sediments from the summit and flanks of southern Hydrate Ridge, Sites 1244-1250, ODP Leg 204. In: Tr?hu, AM; Bohrmann, G; Torres, ME; Colwell, FS (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 204, 1-19

    Gr?cia, Eul?lia / Ercilla, Gemma / Larrasoa?a, Juan C / Martinez-Ruiz, Francisca C / Pi?ero, Elena / Vizcaino, Alexis

    2006  

    Abstract: We present grain size, granulometric statistical parameters, and calcium carbonate content of sediment samples from the summit and east and west flanks of southern Hydrate Ridge (Sites 1244-1250). These data are compared with magnetic susceptibility ... ...

    Abstract We present grain size, granulometric statistical parameters, and calcium carbonate content of sediment samples from the summit and east and west flanks of southern Hydrate Ridge (Sites 1244-1250). These data are compared with magnetic susceptibility measurements from the same intervals. Bulk and clay mineralogy from Sites 1244 (east flank), 1247 (west flank), and 1250 (summit) are also presented. The integration of these data allows us to characterize the main sedimentary facies and composition of the Quaternary age sediments from southern Hydrate Ridge.
    Language English
    Dates of publication 2006-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Conference proceedings ; Online
    Note This dataset is supplement to doi:10.2973/odp.proc.sr.204.110.2006
    DOI 10.1594/PANGAEA.774682
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

    More links

    Kategorien

To top